diff --git a/types/eslint/eslint-tests.ts b/types/eslint/eslint-tests.ts
index 6a81d69c8a..b0c3c1966d 100644
--- a/types/eslint/eslint-tests.ts
+++ b/types/eslint/eslint-tests.ts
@@ -446,6 +446,7 @@ let cli: CLIEngine;
 
 cli = new CLIEngine({ allowInlineConfig: false });
 cli = new CLIEngine({ baseConfig: false });
+cli = new CLIEngine({ baseConfig: { extends: ['lynt'] }});
 cli = new CLIEngine({ cache: true });
 cli = new CLIEngine({ cacheFile: 'foo' });
 cli = new CLIEngine({ configFile: 'foo' });
diff --git a/types/eslint/index.d.ts b/types/eslint/index.d.ts
index 89067f97c8..031ab984f7 100644
--- a/types/eslint/index.d.ts
+++ b/types/eslint/index.d.ts
@@ -483,7 +483,7 @@ export class CLIEngine {
 export namespace CLIEngine {
     class Options {
         allowInlineConfig?: boolean;
-        baseConfig?: boolean;
+        baseConfig?: false | { [name: string]: any };
         cache?: boolean;
         cacheFile?: string;
         cacheLocation?: string;